About 9171 pounds if the water is at 4C, a little less if the water is hot. You did not give the weight of the empty spa so you would have to add that to the weight of the water provided.
After selecting a location for the spa pool, it is necessary to build a base that will be strong enough to support the weight of the pool, water and occupants. It is then necessary to install an electrical connection to the pool. At this point, the pool will need to be filled with water and chemicals must be added until the water is "balanced". There are test strips that can be used to determine the correct chemical levels. http://www.ehow.com/how_4925553_install-spa-pool.html
The same as you would a fresh water spa.
No spa water is not pure there are other things added to the water
The check valve between the spa and the pool is defective.
The water of your new plaster finished pool might turn green when you added chlorine because of iron in your water. You pool generally needs to be filled with water that has been filtered for iron.
The woman at the desk of the spa said it is a small crock pot filled with water and drops of essential oil - Eucalyptus, Lemongrass, Geranium and Lavander.
There should be valves to redirect the water to and from the spa. Ken
I would NOT do that unless I were certain that the spa was built and designed to handle the change. Salt water can do serious damage to components that were not designed to withstand it.
Hot tubs are tubs filled with hot water. A spa is a place you go to relax and get a massage therapy and such of that nature. Hot tubs you can install in your home.
The Pritikin Spa follows their weight loss plan, so at their spa they do typically have a majority of healthy foods. They aren't so much diet foods, but foods that are more healthy for your body and help you lose weight, but often do still taste good.
When you have a spa used by the public you want to drain it often. The water in the spa should always be clear and clean.
It depends on what was in the spa. If was just hot water, then it should be fine. If it was dirty water, monitor the dog carefully for any signs of sickness.